[JohnDeere318Guy]

Happy New Year! Starting off this year getting a 3057 running. I recently picked up a 3057 Bricktop with the D432 engine. I bought it not running.

First I gave it a shot of carb cleaner to see what it would do and it ran for a few seconds. The gas in the tank is old but they had the valve closed. I drained the old gas and then took off the carburetor to give it a cleaning. It was pretty clean to start with so I checked the jet and gave the rest of the carb a good cleaning.

Today I put the carb back together and put it back on the engine and filled it with fresh mix. It still will not run by itself and will only run with a shot of carb cleaner. I can keep it running on carb cleaner but it will not continue to run.

What should I do next? Also, I’m not quite sure where to adjust the mixture with the little green wheel to on the top of the carb.

On a side note, I checked the spark and it is good (bright blue) and did a compression test and it has 71 lbs. From having the carb off the inside of the crank case is exceptionally clean.

 

[Brad]

Not that familiar with the carb on this model without taking a look, but you won't want to keep running it on carb cleaner. That will take the oil film off the bearings, etc, inside the crankcase. Kind of like running a 4 cycle with no oil.

 

[Lawnboy77]

Well assuming that you got the carb nice and clean with all parts in the carb serviceable, ie float good and set right to achieve the right level of fuel in the bowl, and you adjusted the carb mixture wheel about 2 turns from seated. You have good spark and that is evident in the fact that it will run on primer shots. Cylinder compression checked and extremely good for a D-400...so in my mind that leaves crankcase compression as the likely culprit, and that usually indicates that the engine is just not pulling fresh fuel mix on it own due to crank seals faulty and/or blockage in the exhaust. When you are squirting fuel mix directly in the throat of the carb you could be compensating for a lack of vacuum that a 2 stroke needs to pick up fuel on its own, which is the reason the crankcases need to be sealed well and they need to breath nice and easy with little restrictions in the exhaust.

 

[JohnDeere318Guy]

Well assuming that you got the carb nice and clean with all parts in the carb serviceable, ie float good and set right to achieve the right level of fuel in the bowl, and you adjusted the carb mixture wheel about 2 turns from seated. You have good spark and that is evident in the fact that it will run on primer shots. Cylinder compression checked and extremely good for a D-400...so in my mind that leaves crankcase compression as the likely culprit, and that usually indicates that the engine is just not pulling fresh fuel mix on it own due to crank seals faulty and/or blockage in the exhaust. When you are squirting fuel mix directly in the throat of the carb you could be compensating for a lack of vacuum that a 2 stroke needs to pick up fuel on its own, which is the reason the crankcases need to be sealed well and they need to breath nice and easy with little restrictions in the exhaust.

Thanks for the tips. I'll be looking into the crank seal and exhaust ports next once I take the muffler off. I'll report back with my findings.

 

[Lawnboy77]

One thing to add on the adjustment of the carb. It is typical to set it at 2 turns from seated after it has been disassembled and cleaned just to get it started, but it will typically be running rich after it warms a bit with 2 turns out, so once warm you can slowly turn the adjustment wheel clockwise to lean it out a bit and if you have a tach to check RPMs while it's running you can run it in clockwise until it runs the highest RPM, then back off a 1/4 to 1/2 turn to get that good burble idle. If you don't have a tach no biggie, you can just go by the sound to determine speed.

 

[JohnDeere318Guy]

One thing to add on the adjustment of the carb. It is typical to set it at 2 turns from seated after it has been disassembled and cleaned just to get it started, but it will typically be running rich after it warms a bit with 2 turns out, so once warm you can slowly turn the adjustment wheel clockwise to lean it out a bit and if you have a tach to check RPMs while it's running you can run it in clockwise until it runs the highest RPM, then back off a 1/4 to 1/2 turn to get that good burble idle. If you don't have a tach no biggie, you can just go by the sound to determine speed.

I'll definitely keep that in mind. I've had it backwards the whole time. When I put the carb back on I turned it all of the way out. Is it worth trying to start it again with it set a two turns from seated and see if it will run? I don't have high hopes due to the other factors and possible lack of vacuum, but I could give it a try.

 

[Lawnboy77]

Yes, definitely worth trying again. If you had the needle that far out it could very well have created an air leak that prevents enough fuel being drawn up throw the nozzle to run on it’s own.

 

[JohnDeere318Guy]

Update: I was just was out in the shop and tried to start it with the needle two turns out and it would not start. I then put some mix in a spray bottle and tried again, it fired right up and ran strong and I was able to keep it running as long as I kept spraying the gas. I also tried it with the needle leaned out pretty far and it ran great on spray.

Looks like it's time to figure out this crankcase compression issue.

 

[LawnBoy90]

I second checking the crank seals and look out for any possible gasket leaks. 71 lbs compression is a little bit more on the tired side and fresh seals will get the engine running good again. Before tearing into it again attempt to richen the mix up a little by turning the mixture knob about an eighth of a turn out from two turns.

Another possible problem is that your gas tank screen is clogged with debris or varnish. That happens more often than you think on those old bricktops.

 

[Lawnboy2018]

Yes good point on fuel blockage. Try with the fuel valve off seperating the fuel line at the carburator and then opening the fuel valve and collecting fuel to verify no blockage. There should be good trickle of fuel flowing. If so, I suggest removing the carburetor bowl to verify fuel is present and the needle is not stock closed. You mentioned you serviced the carburetor so main jet should be clear. With the engine running, even on carb cleaner, you must see fuel being sucked in from the emulsion tube/main jet with the air filter element removed. If not recheck the main jet.